He Built His Own Robotic "Tractobots"

Kyler Laird watched his Deere tractor and planter put in 500 acres of corn while he sat in a nearby pickup truck working on other farm business. He has also drilled soybeans and done vertical tillage, all while sitting in his truck. Last fall he signaled the tractor on his grain cart to bring it to the combine when he needed to dump. Laird calls the tractors he uses "tractobots".
"I have set up 4 tractobots," says Laird. ?My first was a Deere 420 garden tractor. Then I modified an old Massey Ferguson to plant soybeans and a Challenger for vertical tillage and pulling a grain cart. Tractobot 03 is a 6330 Deere for corn planting."
Laird has a bachelor?s degree in computer science and a master?s degree in agricultural systems management, but is self-taught on robotics. He actually started out working with a remote control wheelchair, using a motor controller and computer to control it. The Deere 420 was his first real step in autonomous tractors.
"I bought the 420 at an auction, ripped out the hydraulics and redid it, learning how to make hard hydraulic lines and designing the electronic system using off-the-shelf components," says Laird. 
He set it up so a computer could control the ignition, hydrostatic transmission and clutch. He had to figure out how to electronically control the hydraulic steering and control the rockshaft to lift and lower implements. He installed GPS for positioning.
"I wrote the software and tried it," recalls Laird. "I configured it to drive from one point to another and avoid obstacles. It worked fairly well. I kept refining it."
His next step was a 2745 Massey Ferguson using the same style computer interface and programming. He used electric actuators to control the steering and to push the clutch in and an electric solenoid valve for the implements. He tested it out on a disk and then drilled soybeans with it. 
Laird traded a Deere for an MT765 Challenger, in large part because of dealer support. While it was difficult getting information from Deere, the AGCO dealer was helpful.
"They brought out 2 huge binders filled with schematics before I even bought it," says Laird. "It was super easy to interface with."
In some ways, setting it up for autonomous use was easier than either previous tractor. The hardware already operated electronically, and it had a guidance system already installed.
"I used the same program code on the Challenger, and it went through the field on a straight line at 19 miles per hour,? says Laird." The vertical tillage was wonderful. It ran at up to 7 miles per hour. It was more fun sitting in the truck and watching it than it was running it manually."
Laird is still working on the transmission control. He uses a remote to throttle up and down. "It's fun watching it at the row ends, slipping around," he says. ?It does the flip to return a whole lot better than I could."
This past summer he took first place honors for best autonomous planting technology at the AgBOT Challenge, held annually at Gerrish Farms, Rockville, Ind. He entered the 6330 and 8-row MaxEmerge planter he planted his corn with this past spring.
To automate the older Deere, he added an autosteer valve and a steering angle sensor modified from an auto part. He also used linear actuators for the lever on the transmission and for the reverser.  
Initially he used a Verizon smartphone for in-field location. When it encountered a dead spot in a field caused by a nearby billboard, Laird stopped the tractor short of driving through the billboard. 
"I installed a larger antenna to eliminate dead spots," says Laird.
Laird continues to refine his tractobots. He has replaced the smartphone on the 6330 with GNASS GPS receivers. All 3 full-size tractors can be driven manually as well as autonomously. He drives them to the field and then turns them loose after setting the electronic boundaries. Each generation gets better, with the goal of eliminating the need for a tractor cab.
"Tractors with guidance systems pretty much do it all now with auto steer," says Laird. "I have a Deere 280R with all the technology, leather seats, heat and radio. It's all a waste of money. I'm looking for tractors 2 generations back that I can modify to do what I want."